From fb8ffd7cfc68b3dc44e182356a207d784cb30b34 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <yamada.m@jp.panasonic.com>
Date: Thu, 4 Sep 2014 02:40:58 +0900
Subject: compiler*.h: sync include/linux/compiler*.h with Linux 3.16

Copy them from Linux v3.16 tag.
My main motivation of this commit is to add compiler-clang.h.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Jeroen Hofstee <jeroen@myspectrum.nl>
---
 include/linux/compiler-clang.h | 12 ++++++
 include/linux/compiler-gcc.h   | 57 ++++++++++++++++++--------
 include/linux/compiler-gcc3.h  | 20 ++++-----
 include/linux/compiler-gcc4.h  | 59 +++++++++++++++++++--------
 include/linux/compiler-intel.h | 40 ++++++++++++++++++
 include/linux/compiler.h       | 92 +++++++++++++++++++++++++++++++++++++++++-
 6 files changed, 236 insertions(+), 44 deletions(-)
 create mode 100644 include/linux/compiler-clang.h
 create mode 100644 include/linux/compiler-intel.h

--- /dev/null
+++ b/include/linux/compiler-clang.h
@@ -0,0 +1,12 @@
+#ifndef __LINUX_COMPILER_H
+#error "Please don't include <linux/compiler-clang.h> directly, include <linux/compiler.h> instead."
+#endif
+
+/* Some compiler specific definitions are overwritten here
+ * for Clang compiler
+ */
+
+#ifdef uninitialized_var
+#undef uninitialized_var
+#define uninitialized_var(x) x = *(&(x))
+#endif
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -5,6 +5,9 @@
 /*
  * Common definitions for all gcc versions go here.
  */
+#define GCC_VERSION (__GNUC__ * 10000 \
+		   + __GNUC_MINOR__ * 100 \
+		   + __GNUC_PATCHLEVEL__)
 
 
 /* Optimization barrier */
@@ -34,9 +37,15 @@
     __asm__ ("" : "=r"(__ptr) : "0"(ptr));		\
     (typeof(ptr)) (__ptr + (off)); })
 
+/* Make the optimizer believe the variable can be manipulated arbitrarily. */
+#define OPTIMIZER_HIDE_VAR(var) __asm__ ("" : "=r" (var) : "0" (var))
+
+#ifdef __CHECKER__
+#define __must_be_array(arr) 0
+#else
 /* &a[0] degrades to a pointer: a different type from an array */
-#define __must_be_array(a) \
-  BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0])))
+#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
+#endif
 
 /*
  * Force always-inline if the user requests it so via the .config,
@@ -44,15 +53,18 @@
  */
 #if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
     !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4)
-# define inline		inline		__attribute__((always_inline))
-# define __inline__	__inline__	__attribute__((always_inline))
-# define __inline	__inline	__attribute__((always_inline))
+# define inline		inline		__attribute__((always_inline)) notrace
+# define __inline__	__inline__	__attribute__((always_inline)) notrace
+# define __inline	__inline	__attribute__((always_inline)) notrace
+#else
+/* A lot of inline functions can cause havoc with function tracing */
+# define inline		inline		notrace
+# define __inline__	__inline__	notrace
+# define __inline	__inline	notrace
 #endif
 
 #define __deprecated			__attribute__((deprecated))
-#ifndef __packed
-# define __packed			__attribute__((packed))
-#endif
+#define __packed			__attribute__((packed))
 #define __weak				__attribute__((weak))
 
 /*
@@ -60,8 +72,12 @@
  * naked functions because then mcount is called without stack and frame pointer
  * being set up and there is no chance to restore the lr register to the value
  * before mcount was called.
+ *
+ * The asm() bodies of naked functions often depend on standard calling conventions,
+ * therefore they must be noinline and noclone.  GCC 4.[56] currently fail to enforce
+ * this, so we must do so ourselves.  See GCC PR44290.
  */
-#define __naked				__attribute__((naked)) notrace
+#define __naked				__attribute__((naked)) noinline __noclone notrace
 
 #define __noreturn			__attribute__((noreturn))
 
@@ -75,13 +91,10 @@
  * would be.
  * [...]
  */
-#ifndef __pure
-# define __pure				__attribute__((pure))
-#endif
-#ifndef __aligned
-# define __aligned(x)			__attribute__((aligned(x)))
-#endif
-#define __printf(a,b)			__attribute__((format(printf,a,b)))
+#define __pure				__attribute__((pure))
+#define __aligned(x)			__attribute__((aligned(x)))
+#define __printf(a, b)			__attribute__((format(printf, a, b)))
+#define __scanf(a, b)			__attribute__((format(scanf, a, b)))
 #define  noinline			__attribute__((noinline))
 #define __attribute_const__		__attribute__((__const__))
 #define __maybe_unused			__attribute__((unused))
@@ -91,3 +104,15 @@
 #define _gcc_header(x) __gcc_header(linux/compiler-gcc##x.h)
 #define gcc_header(x) _gcc_header(x)
 #include gcc_header(__GNUC__)
+
+#if !defined(__noclone)
+#define __noclone	/* not needed */
+#endif
+
+/*
+ * A trick to suppress uninitialized variable warning without generating any
+ * code
+ */
+#define uninitialized_var(x) x = x
+
+#define __always_inline		inline __attribute__((always_inline))
--- a/include/linux/compiler-gcc3.h
+++ b/include/linux/compiler-gcc3.h
@@ -2,20 +2,22 @@
 #error "Please don't include <linux/compiler-gcc3.h> directly, include <linux/compiler.h> instead."
 #endif
 
-#if __GNUC_MINOR__ >= 3
+#if GCC_VERSION < 30200
+# error Sorry, your compiler is too old - please upgrade it.
+#endif
+
+#if GCC_VERSION >= 30300
 # define __used			__attribute__((__used__))
 #else
 # define __used			__attribute__((__unused__))
 #endif
 
-#if __GNUC_MINOR__ >= 4
+#if GCC_VERSION >= 30400
 #define __must_check		__attribute__((warn_unused_result))
 #endif
 
-/*
- * A trick to suppress uninitialized variable warning without generating any
- * code
- */
-#define uninitialized_var(x) x = x
-
-#define __always_inline		inline __attribute__((always_inline))
+#ifdef CONFIG_GCOV_KERNEL
+# if GCC_VERSION < 30400
+#   error "GCOV profiling support for gcc versions below 3.4 not included"
+# endif /* __GNUC_MINOR__ */
+#endif /* CONFIG_GCOV_KERNEL */
--- a/include/linux/compiler-gcc4.h
+++ b/include/linux/compiler-gcc4.h
@@ -4,7 +4,7 @@
 
 /* GCC 4.1.[01] miscompiles __weak */
 #ifdef __KERNEL__
-# if __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ <= 1
+# if GCC_VERSION >= 40100 &&  GCC_VERSION <= 40101
 #  error Your version of gcc miscompiles the __weak directive
 # endif
 #endif
@@ -12,17 +12,12 @@
 #define __used			__attribute__((__used__))
 #define __must_check 		__attribute__((warn_unused_result))
 #define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
-#ifndef __always_inline
-# define __always_inline		inline __attribute__((always_inline))
-#endif
 
-/*
- * A trick to suppress uninitialized variable warning without generating any
- * code
- */
-#define uninitialized_var(x) x = x
+#if GCC_VERSION >= 40100 && GCC_VERSION < 40600
+# define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
+#endif
 
-#if __GNUC_MINOR__ >= 3
+#if GCC_VERSION >= 40300
 /* Mark functions as cold. gcc will assume any path leading to a call
    to them will be unlikely.  This means a lot of manual unlikely()s
    are unnecessary now for any paths leading to the usual suspects
@@ -38,8 +33,15 @@
    the kernel context */
 #define __cold			__attribute__((__cold__))
 
+#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
 
-#if __GNUC_MINOR__ >= 5
+#ifndef __CHECKER__
+# define __compiletime_warning(message) __attribute__((warning(message)))
+# define __compiletime_error(message) __attribute__((error(message)))
+#endif /* __CHECKER__ */
+#endif /* GCC_VERSION >= 40300 */
+
+#if GCC_VERSION >= 40500
 /*
  * Mark a position in code as unreachable.  This can be used to
  * suppress control flow warnings after asm blocks that transfer
@@ -50,14 +52,37 @@
  * unreleased.  Really, we need to have autoconf for the kernel.
  */
 #define unreachable() __builtin_unreachable()
-#endif
 
+/* Mark a function definition as prohibited from being cloned. */
+#define __noclone	__attribute__((__noclone__))
+
+#endif /* GCC_VERSION >= 40500 */
+
+#if GCC_VERSION >= 40600
+/*
+ * Tell the optimizer that something else uses this function or variable.
+ */
+#define __visible __attribute__((externally_visible))
 #endif
 
-#if __GNUC_MINOR__ > 0
-#define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
+/*
+ * GCC 'asm goto' miscompiles certain code sequences:
+ *
+ *   http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
+ *
+ * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
+ * Fixed in GCC 4.8.2 and later versions.
+ *
+ * (asm goto is automatically volatile - the naming reflects this.)
+ */
+#define asm_volatile_goto(x...)	do { asm goto(x); asm (""); } while (0)
+
+#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP
+#if GCC_VERSION >= 40400
+#define __HAVE_BUILTIN_BSWAP32__
+#define __HAVE_BUILTIN_BSWAP64__
 #endif
-#if __GNUC_MINOR__ >= 4
-#define __compiletime_warning(message) __attribute__((warning(message)))
-#define __compiletime_error(message) __attribute__((error(message)))
+#if GCC_VERSION >= 40800 || (defined(__powerpc__) && GCC_VERSION >= 40600)
+#define __HAVE_BUILTIN_BSWAP16__
 #endif
+#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
--- /dev/null
+++ b/include/linux/compiler-intel.h
@@ -0,0 +1,40 @@
+#ifndef __LINUX_COMPILER_H
+#error "Please don't include <linux/compiler-intel.h> directly, include <linux/compiler.h> instead."
+#endif
+
+#ifdef __ECC
+
+/* Some compiler specific definitions are overwritten here
+ * for Intel ECC compiler
+ */
+
+#include <asm/intrinsics.h>
+
+/* Intel ECC compiler doesn't support gcc specific asm stmts.
+ * It uses intrinsics to do the equivalent things.
+ */
+#undef RELOC_HIDE
+#undef OPTIMIZER_HIDE_VAR
+
+#define RELOC_HIDE(ptr, off)					\
+  ({ unsigned long __ptr;					\
+     __ptr = (unsigned long) (ptr);				\
+    (typeof(ptr)) (__ptr + (off)); })
+
+/* This should act as an optimization barrier on var.
+ * Given that this compiler does not have inline assembly, a compiler barrier
+ * is the best we can do.
+ */
+#define OPTIMIZER_HIDE_VAR(var) barrier()
+
+/* Intel ECC compiler doesn't support __builtin_types_compatible_p() */
+#define __must_be_array(a) 0
+
+#endif
+
+#ifndef __HAVE_BUILTIN_BSWAP16__
+/* icc has this, but it's called _bswap16 */
+#define __HAVE_BUILTIN_BSWAP16__
+#define __builtin_bswap16 _bswap16
+#endif
+
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -5,16 +5,23 @@
 
 #ifdef __CHECKER__
 # define __user		__attribute__((noderef, address_space(1)))
-# define __kernel	/* default address space */
+# define __kernel	__attribute__((address_space(0)))
 # define __safe		__attribute__((safe))
 # define __force	__attribute__((force))
 # define __nocast	__attribute__((nocast))
 # define __iomem	__attribute__((noderef, address_space(2)))
+# define __must_hold(x)	__attribute__((context(x,1,1)))
 # define __acquires(x)	__attribute__((context(x,0,1)))
 # define __releases(x)	__attribute__((context(x,1,0)))
 # define __acquire(x)	__context__(x,1)
 # define __release(x)	__context__(x,-1)
 # define __cond_lock(x,c)	((c) ? ({ __acquire(x); 1; }) : 0)
+# define __percpu	__attribute__((noderef, address_space(3)))
+#ifdef CONFIG_SPARSE_RCU_POINTER
+# define __rcu		__attribute__((noderef, address_space(4)))
+#else
+# define __rcu
+#endif
 extern void __chk_user_ptr(const volatile void __user *);
 extern void __chk_io_ptr(const volatile void __iomem *);
 #else
@@ -27,13 +34,20 @@ extern void __chk_io_ptr(const volatile
 # define __chk_user_ptr(x) (void)0
 # define __chk_io_ptr(x) (void)0
 # define __builtin_warning(x, y...) (1)
+# define __must_hold(x)
 # define __acquires(x)
 # define __releases(x)
 # define __acquire(x) (void)0
 # define __release(x) (void)0
 # define __cond_lock(x,c) (c)
+# define __percpu
+# define __rcu
 #endif
 
+/* Indirect macros required for expanded argument pasting, eg. __LINE__. */
+#define ___PASTE(a,b) a##b
+#define __PASTE(a,b) ___PASTE(a,b)
+
 #ifdef __KERNEL__
 
 #ifdef __GNUC__
@@ -49,6 +63,13 @@ extern void __chk_io_ptr(const volatile
 # include <linux/compiler-intel.h>
 #endif
 
+/* Clang compiler defines __GNUC__. So we will overwrite implementations
+ * coming from above header files here
+ */
+#ifdef __clang__
+#include <linux/compiler-clang.h>
+#endif
+
 /*
  * Generic compiler-dependent macros required for kernel
  * build go below this comment. Actual compiler/compiler version
@@ -156,6 +177,15 @@ void ftrace_likely_update(struct ftrace_
     (typeof(ptr)) (__ptr + (off)); })
 #endif
 
+#ifndef OPTIMIZER_HIDE_VAR
+#define OPTIMIZER_HIDE_VAR(var) barrier()
+#endif
+
+/* Not-quite-unique ID. */
+#ifndef __UNIQUE_ID
+# define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__)
+#endif
+
 #endif /* __KERNEL__ */
 
 #endif /* __ASSEMBLY__ */
@@ -228,7 +258,7 @@ void ftrace_likely_update(struct ftrace_
 
 /*
  * Rather then using noinline to prevent stack consumption, use
- * noinline_for_stack instead.  For documentaiton reasons.
+ * noinline_for_stack instead.  For documentation reasons.
  */
 #define noinline_for_stack noinline
 
@@ -270,11 +300,20 @@ void ftrace_likely_update(struct ftrace_
 # define __section(S) __attribute__ ((__section__(#S)))
 #endif
 
+#ifndef __visible
+#define __visible
+#endif
+
 /* Are two types/vars the same type (ignoring qualifiers)? */
 #ifndef __same_type
 # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
 #endif
 
+/* Is this type a native word size -- useful for atomic operations */
+#ifndef __native_word
+# define __native_word(t) (sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
+#endif
+
 /* Compile time object size, -1 for unknown */
 #ifndef __compiletime_object_size
 # define __compiletime_object_size(obj) -1
@@ -284,7 +323,48 @@ void ftrace_likely_update(struct ftrace_
 #endif
 #ifndef __compiletime_error
 # define __compiletime_error(message)
+/*
+ * Sparse complains of variable sized arrays due to the temporary variable in
+ * __compiletime_assert. Unfortunately we can't just expand it out to make
+ * sparse see a constant array size without breaking compiletime_assert on old
+ * versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether.
+ */
+# ifndef __CHECKER__
+#  define __compiletime_error_fallback(condition) \
+	do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
+# endif
 #endif
+#ifndef __compiletime_error_fallback
+# define __compiletime_error_fallback(condition) do { } while (0)
+#endif
+
+#define __compiletime_assert(condition, msg, prefix, suffix)		\
+	do {								\
+		bool __cond = !(condition);				\
+		extern void prefix ## suffix(void) __compiletime_error(msg); \
+		if (__cond)						\
+			prefix ## suffix();				\
+		__compiletime_error_fallback(__cond);			\
+	} while (0)
+
+#define _compiletime_assert(condition, msg, prefix, suffix) \
+	__compiletime_assert(condition, msg, prefix, suffix)
+
+/**
+ * compiletime_assert - break build and emit msg if condition is false
+ * @condition: a compile-time constant condition to check
+ * @msg:       a message to emit if condition is false
+ *
+ * In tradition of POSIX assert, this macro will break the build if the
+ * supplied condition is *false*, emitting the supplied error message if the
+ * compiler has support to do so.
+ */
+#define compiletime_assert(condition, msg) \
+	_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
+
+#define compiletime_assert_atomic_type(t)				\
+	compiletime_assert(__native_word(t),				\
+		"Need native word sized stores/loads for atomicity.")
 
 /*
  * Prevent the compiler from merging or refetching accesses.  The compiler
@@ -300,4 +380,12 @@ void ftrace_likely_update(struct ftrace_
  */
 #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
 
+/* Ignore/forbid kprobes attach on very low level functions marked by this attribute: */
+#ifdef CONFIG_KPROBES
+# define __kprobes	__attribute__((__section__(".kprobes.text")))
+# define nokprobe_inline	__always_inline
+#else
+# define __kprobes
+# define nokprobe_inline	inline
+#endif
 #endif /* __LINUX_COMPILER_H */
